From the prior art semi-trailing arm axles for motor vehicles are known. In these axles the wheel carrier is integrated in a solid semi-trailing arm, which in turn is, as a rule, mounted by means of two rubber mountings on the vehicle body or on a support frame so that it can rotate, whereas the wheels of the axle are mounted on the semi-trailing arm at least via the wheel bearings. By virtue of the sweepback and elevation angles, the tracking and camber variation can be adjusted by the spring deflection. Besides the semi-trailing arm, which serves as the sole wheel-guiding element, the semi-trailing arm axle has for each wheel a body spring usually in the form of a spiral spring and a vibration damper, which are respectively fixed on the semi-trailing arm. The semi-trailing arms can also be fixed on an auxiliary support frame, which constitutes the connecting element to the vehicle's body or its chassis.
For example, EP 0754575 B1 describes a semi-trailing arm suspension for connecting a vehicle wheel to the vehicle's body, such that the suspension comprises a wheel carrier for the rotatable support of the wheel, spring means for prestressing the wheel carrier in a downward direction relative to the body, and a linkage mechanism arrangement for controlling the movement of the wheel carrier relative to the vehicle body, wherein the hinge mechanism arrangement comprises a first control arm with an inwardly-directed end connected to part of the vehicle body so that it can rotate relative thereto about a generally horizontal rotation axis, and an outer end connected to the wheel carrier, such that in relation to the vehicle body the first control arm extends, from its inwardly-directed end to its outwardly-directed end, backward and outward.
The known semi-trailing arm suspension comprises a connection means with a second control arm having a first end connected to part of the vehicle body and able to rotate relative thereto about a generally horizontal axis, and a second end connected to the wheel carrier, such that the wheel carrier can rotate relative to the first control arm about a substantially vertical axis, and the connection means contains a further linkage mechanism which is connected at one point to part of the vehicle body, which, relative to the point where the second control arm is connected to the vehicle body, lies outside and to the rear of the imaginary line extending between the connection point of the first control arm to the body and the connection point of the second control arm to the body. In this case it is provided that the first control arm extends in a generally transverse direction, the second control arm is positioned ahead of the first control arm, and the first and second control arms converge in such manner that they intersect at a point on imaginary lines passing through the connection points of the first and second control arms with the wheel carriers and the vehicle body outside the center of the wheel and to the rear of the wheel's rotational axis, so that the further linkage mechanism tends to cause the wheel carrier to rotate relative to the vehicle body about the substantially vertical axis as a reaction to vertical movement of the wheel. Preferably, the further linkage mechanism is connected to the wheel carrier by the second control arm.
Furthermore, from EP 1288028 A2 an individual wheel suspension of a semi-trailing arm axle with at least two degrees of freedom is known, which comprises at least two flexible control arms connected to the respective wheel carriers and the body, such that owing to their flexible design and geometry the control arms enable a third degree of freedom of the individual wheel suspension about an axis of predetermined orientation, the axis being defined by the intersection of the planes of the two control arms.
EP 1831037 A1 describes a spring mounted axle for a vehicle, that comprises for each wheel a control arm which is connected to the body of the vehicle and enables a spring deflection of the wheel, and a transversely arranged torsion element such that each end of the torsion element is connected rigidly to the control arm associated with the respective wheel in order to form in each case a rigid part of the axle, the two rigid parts of the axle are connected to one another by a torsional component and the wheel carriers are connected by a first and second control arm each to a respective rigid part of the axle. In this case, by virtue of the articulated connections between the wheel carriers and the first and second control arms and between the first and second control arms and the rigid parts of the axle, substantially perpendicular axes are defined.